Method and apparatus for sharpening hardened tools

ABSTRACT

An application for an apparatus for sharpening a cutting blade includes a source of high pressure water stream capable of cutting steel and a sharpening jig for positioning and holding the cutting blade perpendicular to the high pressure water stream, the sharpening jig provides a mechanism for moving the cutting blade so that a cutting edge of the cutting blade predictably passes beneath the high pressure water.

FIELD OF THE INVENTION

This invention relates to the field of hardened tools and moreparticularly to a method for sharpening hardened tools such as diamondalloy tool bits.

BACKGROUND OF THE INVENTION

Stone, such as marble and granite, is often cut using a rotating blademade with diamond. In order for such a blade to efficiently cut stone,its cutting edge must be sharp or, approximately at right angles. Assuch a blade is used, the edges often round resulting in a dull bladethat is less effective in cutting stone or, more significant, a bladethat places undue stress on the attached saw, causing stalling or aburned-out motor.

Prior to the present invention, to extend the life of these expensiveblades, the blades were sharpened by using a hard grinding wheel. Such aprocess improves the life of the blade, but does not completely andevenly sharpen the blade. Because the blade is so hard, the grindingwheel develops ruts as it sharpens the blade. The ruts are usuallycurved, therefore, do not sharpen the blade edge at a right angle. Partsof the blade that are sharpened when the grinding wheel is new are oftensharper (flatter, right angled) than parts that are sharpened when thegrinding wheel is worn and has these ruts. This often results in anunbalanced blade that vibrates or wobbles when used.

Water jet or fluid jet cutting systems are known as evidenced by U.S.Pat. No. 5,782,673 to Warehime. This patent describes a fluid jetcutting and shaping system with an X-Y table beneath the fluid jet forpositioning and moving the object to be cut.

What is needed is a method and apparatus for sharpening diamond edgeblades and other very hard blades that repeatedly and consistentlysharpens the surfaces of the blade.

SUMMARY OF THE INVENTION

In one embodiment, an apparatus for sharpening a cutting blade includinga source of a high pressure water stream capable of cutting steel and asharpening jig for positioning and holding the cutting bladeperpendicular to the high pressure water stream, the sharpening jigprovides a mechanism for moving the cutting blade so that a cutting edgeof the cutting blade predictably passes beneath the high pressure waterstream.

In another embodiment, a method of sharpening a diamond cutting tool isdisclosed including providing a diamond cutting tool having a dullcutting edge. A source of high pressure water capable of cutting steelis provided. A sharpening jig positioned beneath the high pressure waterholds the cutting blade of the diamond cutting tool perpendicular to thehigh pressure water while the diamond cutting tool is rotated. As thecutting edge of the diamond cutting tool passes beneath the highpressure water, the dull cutting edge is cut sharp by the high pressurewater, thereby sharpening the diamond cutting tool.

In another embodiment, an apparatus for sharpening a cutting blade isdisclosed including a source of a high pressure water stream capable ofcutting steel and a device for positioning and holding the cutting bladeperpendicular to the high pressure water stream. The device forpositioning and holding the cutting blade is capable of moving thecutting blade so that a cutting edge of the cutting blade predictablypasses beneath the high pressure water stream.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be best understood by those having ordinary skill inthe art by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a plan view of a diamond cutting blade of the priorart.

FIG. 2 illustrates a side view of a sharpened diamond cutting blade ofthe prior art.

FIG. 3 illustrates a side view of a dulled diamond cutting blade of theprior art.

FIG. 4 illustrates a grinding wheel used to sharpen a diamond cuttingblade of the prior art.

FIG. 5 illustrates a system of the present invention for sharpening adiamond cutting blade.

FIG. 6 illustrates a plan view of a diamond cutting tool of the priorart.

FIG. 7 illustrates a system of the present invention for sharpening adiamond cutting tool.

FIG. 8 illustrates a system of the present invention for sharpening adiamond edging tool.

FIG. 9 illustrates an adapter of the present invention for holdingdiamond edging tools within the system of the present invention duringsharpening.

FIG. 10 illustrates a system of the present invention for sharpening acurved diamond edging tool.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the presently preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Throughout the following detailed description,the same reference numerals refer to the same elements in all figures.

Referring to FIG. 1, a plan view of a diamond cutting blade of the priorart will be described. A typical diamond cutting blade 10 of the art hasa cutting surface 14 and a plurality of cutting points 16. The cuttingblade 10 has a center hole 12 for installing the cutting blade 10 on asaw hub (not shown). For proper cutting, the cutting blade 10 must be asclose to round as possible to prevent vibration and wobble on the sawand must be as sharp as possible, especially when cutting hard stonesuch as marble and granite.

Referring to FIG. 2, a side view of a sharpened diamond cutting blade ofthe prior art will be described. The cutting points 16 of the cuttingblade 10 are visible. The edge 14 a of the cutting blade 10 is sharpbeing that it is substantially flat and at substantially a right anglewith a 90 degree tangent of the rotation of the blade.

Referring to FIG. 3, a side view of a dulled diamond cutting blade ofthe prior art will be described. The cutting points 16 of the cuttingblade 10 are visible. The edge 14 b of the cutting blade 10 is dullbeing that it is substantially curved and its edges are not atsubstantially a right angle with a 90 degree tangent of the rotation ofthe blade.

Referring to FIG. 4, a grinding wheel used to sharpen a diamond cuttingblade of the prior art will be described. In the past, a grinding wheel22 or other suitable grinding device was used to flatten the roundededges 14 a of a cutting blade 10 to restore its ability to cut. In thisexample, the grinding wheel 22 is affixed to a shaft 24 by a fastener 26and rotates on the shaft 24. The shaft 24 is coupled to a source ofrotation (not shown). The flat edge of the grinding wheel 22 contactsthe rounded edge 14 a of the dull cutting blade 10 and grinds away therounded edge 14 a until it is flat as in FIG. 2. Unfortunately, thismethod is very time consuming and creates an uneven cutting blade 10because of difficulties in grinding the blade into a balanced, roundblade. Such difficulties are a result of uneven wear of the grindingwheel 22. The grinding wheel 22 begins flat, but as it contacts the edgeof the dull blade 10, it wears proportionately to the surface area thatmust be removed from the edge 14 a of the cutting tool 10, therebyforming ruts in the grinding wheel 22.

Referring to FIG. 5, a system of the present invention for sharpening adiamond cutting blade will be described. High pressure water 52 is usedto cut hard materials such as marble and granite. The water jet 52 is avery high pressure directed stream of water, usually in the range of20,000 to 55,000 psi. The water is forced through an orifice in a jewel.The orifice is typically 0.010″ to 0.015″ in diameter. Some water jetcutters 50 use abrasives suspended in the water to cut harder materialsor cut faster. The present invention works with many known water jetcutters and is not limited to any particular type or style of water jetcutter.

In the exemplary sharpening system of FIG. 5, a diamond cutting blade 10is rotatably affixed to a sharpening jig 30. The sharpening jig 30 has abase 32 and a holding arm 36 attached to the base 32 by a threadedfastener 34 such as a bolt, etc. In this way, the sharpening jig 30 iseasily affixed to the bed of the water jet cutting system (not shown).The cutting blade 10 to be sharpened is affixed to a hub 42/44/46/48consisting of an upper hub 44 and a lower hub 46 and optionally, washersor spacers 44, all held together by a bolt 42 that threads into the base32. The cutting blade turns freely on the hub 42/44/46/48. To reducebending of the cutting blade 10 under the stress of the high pressurewater stream, a standoff 40 is affixed to the base 32 between the topsurface of the base 32 and the cutting blade 10. As shown, the water jet52 from the water jet source 50 (as known in the industry) is directedsubstantially perpendicular to the cutting blade 10. The sharpening jig30 is positioned on the table of the water jet cutting device (notshown) and the water jet is aligned to cut the rounded edge 14 a off ofthe cutting blade 10, forming a sharp edge 14 a. As the rounded edge 14a is cut from one section of the cutting blade 10, the cutting blade 10is rotated on the hub 42/44/46/48 until the entire cutting blade 10 hassharp edges 14 b as shown in FIG. 2.

Referring to FIG. 6, a plan view of a diamond cutting tool of the priorart will be described. Other diamond cutting tools are known in theindustry for cutting holes in stone, for example the cutting tool 60 forcutting faucet holes in stone counter tops. This cutting tool 60 has acutting edge 62 and cutting surfaces 64 as known in the industry.

Referring to FIG. 7, a system of the present invention for sharpening adiamond cutting tool will be described. To sharpen a diamond cuttingtool 60, the cutting tool 60 is threaded onto a threaded shaft 82 thatis connected to a source of rotation, in this example a crank handle 84.Other sources of rotation are known in the industry and all such sourcesare included here within. The threaded shaft 82 passes through and isrotatable held in position by a riser 80 attached to a base 72. The base72 has a holding arm 76 attached to the base 72 by a threaded fastener74 such as a bolt, etc. In this way, the sharpening jig 70 is easilyaffixed to a bed of the water jet cutting system (not shown). Thecutting tool 60 to be sharpened is threaded onto the threaded shaft 82and positioned under the water jet 52 from the water jet source 50 farenough that the rounded edge of the cutting tool 60 is cut off by thewater jet 52. The cutting tool 60 is rotated by the source of rotation(e.g., the crank 84) until the entire cutting surface of the cuttingtool 60 is sharp.

Referring to FIG. 8, a system of the present invention for sharpening adiamond edging tool will be described. This system has a base 91 ontowhich a drive motor 90 is mounted. The shaft 92 of the drive motor 90 isstabilized by a bearing 94 that is affixed to the base 91 by fasteners95 as known in the industry. A chuck 96 holds the edging tool 98. Inthis example, the edging tool 98 is a flat surface edging tool 98 havingangled cutting surfaces 99. To sharpen such a edging tool 98, the edgingtool 98 in the chuck 96 is rotated by the drive motor 90 and the waterjet 52 is positioned to cut the rounded edges of the cutting surfaces99. The water jet 52 is controlled at the water jet system to passacross the entire cutting edge of the edging tool 98 as the edging tool98 rotates, thereby sharpening all edges 99 of the edging tool 98.

Referring to FIG. 9, an adapter of the present invention for holdingdiamond edging tools within the system of the present invention duringsharpening will be described. The adapter 104 has a bit end 102 forinsertion into the chuck 96 (see FIG. 8) and a body 100 that has ahollowed, threaded portion for accepting a threaded cutting tool (notshown).

Referring to FIG. 10, a system of the present invention for sharpening acurved diamond edging tool will be described. Curved diamond edgingtools 110 are known in the industry and used to create bull-nosed edgesor rounded edges for countertops and the like. The sharpening system ofFIG. 8 is used to sharpen curved diamond edging tools 110 by tighteningthe bit end 112 of the curved diamond edging tool 110 in the chuck 96and, as the curved diamond edging tool 110 is rotated by the drive motor90, the water jet 52 passes along the curved cutting surface of thecurved diamond edging tool 110. The travel of the water jet 52 isprogrammed into the water jet system to track the curvature of thecurved diamond edging tool 110.

Equivalent elements can be substituted for the ones set forth above suchthat they perform in substantially the same manner in substantially thesame way for achieving substantially the same result.

It is believed that the system and method of the present invention andmany of its attendant advantages will be understood by the foregoingdescription. It is also believed that it will be apparent that variouschanges may be made in the form, construction and arrangement of thecomponents thereof without departing from the scope and spirit of theinvention or without sacrificing all of its material advantages. Theform herein before described being merely exemplary and explanatoryembodiment thereof. It is the intention of the following claims toencompass and include such changes.

1. An apparatus for sharpening a cutting blade, the apparatuscomprising: a source of a high pressure water stream, the high pressurewater stream capable of cutting steel; and a sharpening jig forpositioning and holding the cutting blade substantially perpendicular tothe high pressure water stream, the sharpening jig providing a means formoving the cutting blade so that a cutting edge of the cutting bladepredictably passes beneath the high pressure water stream.
 2. Theapparatus for sharpening a cutting blade of claim 1, wherein the cuttingblade is a diamond steel circular blade and the sharpening jigcomprises: a base platform; a clamp for holding the base platform to awork table of the source of high pressure water stream; and a hub forholding the diamond steel circular blade perpendicular to the highpressure water stream, the hub enabling rotation of the diamond steelcircular blade.
 3. The apparatus for sharpening a cutting blade of claim2, further comprising a standoff affixed to the base platform betweenthe hub and the high pressure water, the standoff supporting a bottomsurface of the diamond steel circular blade.
 4. The apparatus forsharpening a cutting blade of claim 1, wherein the cutting blade is adiamond steel hole cutting bit and the sharpening jig comprises: a baseplatform; a clamp for holding the base platform to a work table of thesource of high pressure water stream; a riser affixed to the platformand rising above the platform; a threaded shaft rotatably interfacedwith the riser for holding the diamond steel hole cutting bitperpendicular to the high pressure water stream; and a means forrotating the threaded shaft, thereby rotating the diamond steel holecutting bit beneath the high pressure water stream.
 5. The apparatus forsharpening a cutting blade of claim 1, wherein the cutting blade is adiamond steel edging tool and the sharpening jig comprises: a baseplatform; a clamp for holding the base platform to a work table of thesource of high pressure water stream; a motor affixed to the baseplatform, the motor having a shaft; a chuck for holding the diamondsteel edging tool perpendicular to the high pressure water stream, themotor rotating the diamond steel edging tool situated in the chuck. 6.The apparatus for sharpening a cutting blade of claim 5, furthercomprising a bearing, the bearing affixed to the base platform betweenthe chuck and the motor, the shaft passing through the bearing whereasthe bearing supports the shaft.
 7. The apparatus for sharpening acutting blade of claim 5, wherein the source of the high pressure waterstream is programmed to travel over the cutting edge of the diamondsteel edging tool while the diamond steel edging tool is rotated by themotor.
 8. A method of sharpening a diamond cutting tool, the methodcomprising: providing a diamond cutting tool having a dull cutting edge;providing a source of high pressure water, the high pressure watercapable of cutting steel; and providing a sharpening jig for positioningand holding the cutting blade substantially perpendicular to the highpressure water; rotating the diamond cutting tool whereas a cutting edgeof the diamond cutting tool passes beneath the high pressure water andthe dull cutting edge is cut sharp by the high pressure water.
 9. Themethod of claim 8, wherein the cutting blade is a diamond steel circularblade and the sharpening jig comprises: a base platform; a clamp forholding the base platform to a work table of the source of high pressurewater; and a hub for holding the diamond steel circular bladeperpendicular to the high pressure water, the hub enabling the rotatingof the diamond steel circular blade.
 10. The method of claim 9, furthercomprising a standoff affixed to the base platform between the hub andthe high pressure water, the standoff supporting a bottom surface of thediamond steel circular blade.
 11. The method of claim 8, wherein thecutting blade is a diamond steel hole cutting bit and the sharpening jigcomprises: a base platform; a clamp for holding the base platform to awork table of the source of high pressure water; a riser affixed to theplatform and rising above the platform; a threaded shaft rotatablyinterfaced with the riser for holding the diamond steel hole cutting bitperpendicular to the high pressure water; and a means for rotating thethreaded shaft, thereby rotating the diamond steel hole cutting bitbeneath the high pressure water.
 12. The method of claim 8, wherein thecutting blade is a diamond steel edging tool and the sharpening jigcomprises: a base platform; a clamp for holding the base platform to awork table of the source of high pressure water; a motor affixed to thebase platform, the motor having a shaft; a chuck for holding the diamondsteel edging tool perpendicular to the high pressure water, the motorrotating the diamond steel edging tool.
 13. The method of claim 12,further comprising a bearing, the bearing affixed to the base platformbetween the chuck and the motor, the shaft passing through the bearingwhereas the bearing supports the shaft.
 14. The method of claim 12,wherein the source of high pressure water is programmed to travel overthe cutting edge of the diamond steel edging tool while the diamondsteel edging tool is rotated by the motor.
 15. An apparatus forsharpening a cutting blade, the apparatus comprising: a source of a highpressure water stream, the high pressure water stream capable of cuttingsteel; and a means for positioning and holding the cutting bladesubstantially perpendicular to the high pressure water stream, the meansfor positioning and holding the cutting blade perpendicular having ameans for moving the cutting blade so that a cutting edge of the cuttingblade predictably passes beneath the high pressure water stream.
 16. Theapparatus for sharpening a cutting blade of claim 15, wherein thecutting blade is a diamond steel circular blade and the means forpositioning and holding the cutting blade perpendicular comprises: abase platform; a means for holding the base platform to a work table ofthe source of high pressure water stream; and a means for holding thediamond steel circular blade perpendicular to the high pressure waterstream, the means for holding enabling rotation of the diamond steelcircular blade.
 17. The apparatus for sharpening a cutting blade ofclaim 16, further comprising a standoff affixed to the base platformbetween the means for holding and the high pressure water stream, thestandoff supporting a bottom edge of the diamond steel circular blade.18. The apparatus for sharpening a cutting blade of claim 15, whereinthe cutting blade is a diamond steel hole cutting bit and the means forpositioning and holding the cutting blade substantially perpendicularcomprises: a base platform; a means for holding the base platform to awork table of the source of high pressure water stream; a riser affixedto the platform and rising above the platform; a means for holding thediamond steel hole cutting tool, the means for holding rotatablyinterfaced with the riser thereby holding the diamond steel hole cuttingbit perpendicular to the high pressure water stream; and a means forrotating the a means for holding, permitting rotation of the diamondsteel hole cutting bit beneath the high pressure water stream.
 19. Theapparatus for sharpening a cutting blade of claim 15, wherein thecutting blade is a diamond steel edging tool and the means forpositioning and holding the cutting blade perpendicular comprises: abase platform; a means for holding the base platform to a work table ofthe source of high pressure water stream; a means for rotating thediamond steel edging tool affixed to the base platform; a means forholding the diamond steel edging tool interfaced to the means forrotating, the means for holding maintaining the diamond steel edgingtool substantially perpendicular to the high pressure water stream, themeans for rotating adapted to rotate the diamond steel edging tool. 20.The apparatus for sharpening a cutting blade of claim 19, wherein thesource of high pressure water stream is programmed to travel over acutting edge of the diamond steel edging tool while the diamond steeledging tool is rotated by the means for rotating.